Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[michaeldmuehe]

How do you open the ADA Microtube 200 to change the tubes?

[rnolan]

Not that I've had any direct experiance with a MT200, but generally, either take off (unscrew) the top or bottom cover, pull the tubes (you want to change), replace them with an equivalent tube (lots to choose from) and fire it up 

[michaeldmuehe]

the thing is its I dont think it opens up like the MP1,  the top has no screws and when I take the bottom screws out, it dont open like i expected , so the i guess Im asking about how to get to the tubes in the firstplace lol. must be missing some screws lol.  I have the schematics but not the owners manual. This was my old drummers that was killed in a car accident 7 years ago bought it from his son for a 100 bucks. The thing sill cranks, well worth it! 

[Dante]

Rnolan nailed it, you take off the bottom cover (if i remember correctly = IIRC) and the tubes (both of them) are accessible that way.

It's been a few years since I took mine apart, and my memory isn't what it used to be...hell it's half of that  but I believe in using every body part to it's full potential!! 

[rnolan]

Hey Dante, you've been away for a bit ? I'm assuming also it takes a pair of 12AX7s tubes to do the voltage gain and the mosfets do the open current (ala MT100).  I have spec sheets for the MT100 but not the MT200 but they are probably quite similar just more power output for the MT200.  Dante have you done any tube rolling on these to recommend some 12AX7s, I'm sure Mullards, JJs or TUNG-SOLs  would be fine (http://www.dougstubes.com/preamp-tubes/12ax7-ecc83-7025.html) although the role the tube plays in these is a little different to pre-amps as in you want them to be clean, quiet, non-microphonic and transparent as opposed to making killer gain/distortion.

[Dante]

Hey Dante, you've been away for a bit ?

Yeah, I was away for a week, then I needed to recover.

Right about those tubes - you want CLEAN, not gain. It's a power amp = make things loud. Not a Preamp = make things dirty

I do remember hating the GrooveTube 12ax7r2 tubes in that amp. I think I went with some JANs or TungSols...I'll know for sure when I get my amp back, it's at the doc. (the bridged mono is being fixed) You can ask Doug what he recommends, he's given me good advice in the past.